Accelerating action of quinidine on the decay phase of transient outward current in dissociated hippocampal pyramidal neurons of rats.

The effect of quinidine on the transient outward current (IA) in rat hippocampal neurons was studied. Quinidine at 1 x 10(-6) M or more dose-dependently decreased the IA without affecting the current-voltage relationship. Quinidine accelerated the decay phase of the IA, suggesting the blockade of open channels. This result may have an implication on the side effects of quinidine in the central nervous system, since the IA is involved in the control of rhythmic electrical activity of the neurons.